1. What is the tissue that secretes cerebrospinal fluid in the ventricles?

choroid plexus

2. In explaining fluorescence, why is the emission a longer wavelength than the excitation?

energy is lost before a hoton is re-emitted

3. In the knee-jerk reflex, answer either (1) Where is the cell body of the motor neuron? or (2) Where is the cell body of the sensory neuron?

ventral horn in gray matter of spinal cord, in dorsal root ganglion PNS

4. "Your patient is having a stroke. Quick! Give him some TPA." Under what circumstances would tissue plasminogen activator be contraindicated?

hemorrhagic stroke

5. Confocal microscope. Answer either (1) How did they make tau look red and tubulin look green in that textbook micrograph? or (2) What property of the technology allowed Dr Stark's student make a Quicktime movie focusing through the depth of the Drosophila retina?

bind green- or red-emitting fluorophores to secondary antibody that binds primary antibody to tau and tubulin, optical sectioning = low depth of focus

6. "Histochemical fluorescence." What substance was seen in the fluorescence microscope when the tract from the substantia nigra to the striatum (basal ganglia) was visualized?

dopamine combined with formaldehyde

7. "Fluorescent- or gold-labeled secondary body." Answer either (1) What specific molecule does it bind to? or (2) Why gold? (referring to immunocytochemistry)

primary antibody, electron dense

8. Say something about a structural specialization on the postsynaptic dendrite or on the postsynaptic membrane.

spine, postsynaptic density, receptors

9. Keeping in mind what I have said about techniques, what are you actually seeing when you refer to the electron density of a membrane or a synaptic vesicle?

electron dense heavy metals bound to membrane or vesicle contents

10. Give the name of a protein involved in axon transport.

tau kinesin, microtubular protein

11. In the neurons and glia lecture, we referred to two components of the blood brain barrier between the blood and the cerebrospinal fluid. Identify one of these.

capillary endothelium plus astrocyte end foor

12. Using a radioactive label, we can see where that radioactivity gets to in the brain. Name (or describe) that technique.

autoradiography, expose photographic film to histological brain slice

13. Identify a protein that would be found at or near the node of Ranvier but would not be foune (or would be found in much lesser amount) on or near the axon under the myelin.

sodium channels, OMgp=oligodendrocyte glycoprotein

14. Why would you expect membrane to have very high resistance?

except for channels, the hydrophobic milieu of fatty acids of the bilayer of phospholipids would not conduct ions

15. "Multiple sclerosis is an autoimmune disease." Answer either (1) To what protein? or (2) How can you get immune to a protein that belongs in your body?

myelin basic protein, its sequestration from immune surveillance has been compromised

16. An action potential is (1) all-or-none, (2) non-decremental, and (3) in the direction of making the inside of the cell more positive. Pick one of those three attributes and say how a synaptic potential differs if it differs.

potentials can add to each other, they get smaller with distance, they may also be hyperpolarizing

17. "Cole and Curtis's bridge went out of balance." What did we learn from their 1939 work on the squid giant axon with the Wheatstone bridge?

conductance goes up as the action potential passes

18. "A square wave of current injection led to a hyperpolarization that was low pass filtered." That different shape was because of what property of the membrane?


19. In the Goldman equation, concentrations (in and out) of sodium, potassium and chloride, and permeabilities for all three ions, are shown. There is an equivalent circuit (with electrical components) for the Goldman equation. What is used in the circuit model for the sodium permeability? Be thorough enough in your answer to address what happens to sodium permeability during the action potential.

a variable resistor (potentiometer) that lets sodium permeability go up

20. Current flows through (what?) in the patch clamp technique that earned Neher and Sackman the 1991 Nobel Prize.

individual channels

21. Ouabain is applied to the cell. Answer either (1) Why does the membrane potential change by a few mV? or (2) Why doesn't the membrane potential go away right away?

3 sodiums to 2 potassiums make the pump electrogenic, otherwise potentials are based on huge reservoirs of ion gradients that would run down very slowly if the pump were blocked

22. In Hodgkin and Keyne's1955 experiment, what happened to the efflux of radioactive sodium mediated by the "sodium pump" when extracellular potassium, already low, was really lowered?

it decreased sharply because sodium transport relies on exchange with potassium transport

23. Discussing passive spread of a decremental potential, the current spreading down the axoplasm gets smaller with distance from a place where a stimulus is applied. What happened to the current that was no longer going down the axoplasm?

it leaked through the axon membrane's resistance and capacitance

24. What does the space constant and the time constant have to do with why squids have giant axons?

cable equation's space constant varies with the square root of the radius while the time constant is independent of the radius, and the space constant over the time constant of passive spread ought to predict the action potential speed

25. Loss of what hormone, from an adrenalectomy, would make a rat crave salt?


26. The lecture and figures refer to a sodium channel that is about to be depolarized to threshold by an upstream action potential as "closed." Right after the action potential has passed, what term do we use to describe the status of the sodium channel?


27. Why would long QT syndrome limit a person's ability to respond to stress?

inability to have shorter action potential in the ventricualr myocardium would limit how fast the pulse can get

28. Why, when the voltage of the squid giant axon is clamped at +65 mV (inside positive), does the early current flow out instead of in?

despite the fact that sodium is going up against its ion gradient, the driving potential, the voltage minus the sodium equilibrium potential, would drive current that direction

29. A family of "I-T curves" were used by Hodgkin and Huxley to generate two "I-V curves." Say something about these curves.

the "family" was for different voltage clamp levels, giving the V on tie I-V curves. early and late times were chosen tor the two I-V curves. the early curve showed the negative conductance region representing the soduim channel activation

30. "The space clamp meant that voltage clamping was done along the whole axon." Why would this be more useful than firing a real action potential?

realistic (measurable, not infinitessimal) currentscould be measured

31. How much current should be carried by sodium at the sodium equilibrium potential?


32. What are the differences in how four components form a channel for Shaker vs. Electrophorus?

4 proteins for shaker, 4 domains of one protein in electrophorus

33. At one time they thought that the positively charged amino acids in S4 lined the channel, but eventually they agreed that S4 did (what?)?

sensed toe voltage for gating to cause a conformational change for activation

34. Why would pheochromocytoma cells be a reasonable model for studying neurotransmitter release?

can culture adrenal medulla cancer cells which release catecholamines

35. "Ramon y Cajal's 'cell theory' implies that something like a chemical synapse MUST exist (even though they has not been demonstrated yet)" Explain.

the alternate, Golgi's reticular theory, has continuous processes, while separate cells require communication between cells

36. Describe the structural or molecular specializations that form an "electrical synapse."

in gap junction, connexons are formed from hexamers of connexins in register from one cell to the next

37. "There are no inhibitory neuromuscular junctions in the vertebrate." What does that information tell us about "the final common pathway in the integrative action of the nervous system?"

it must be in the spinal motor neuron since there is no integration after that

38. What kind of technique would be needed to determine the reversal potentials for the IPSP and the EPSP?

voltage clamp

39. Activation of the nerve elicited (what? - be specific) at the end plate when Katz decreased the extracellular calcium ion concentration.

miniature end plate potentials, 0, 1, 2, or 3 of them

40. Describe either the freeze-fracture or the transmission electron microscope image of a vesicle in the process of release.

holes (pits), omega figures

41. Why would there be transporter molecules in the vesicle membrane?

to maintain a steep gradient against leakage

42. On the spinal motor neuron, there are synapses onto the dendrites and cell body. A picture was shown of the first synaptic area behind the Drosophila compound eye, and the point was made that invertebrate neuropils we would see later in the semester are similarly organized. How does this synaptic organization differ from that of the vertebrate?

the cell body of the postsynaptic neuron is on the outside of the ganglion, aloof from synapses

43. How could Shibire mutants have temperature sensitive paralysis when the mutation does not block vesicle release?

it blocks recycling of vesicle membrane

44. Why would a doctor give a patient a clostridial protease that cleaves synaptobrevin?

cosmetic dermatologists would discourage wrinkles in the face by blocking neuromuscular junctions

45. What is the target membrane that the vesicle-SNARE latches onto?


46. How is Met-enkephalin produced from pre-proenkephalin A?

it is cleaved from the larger protein

47. Blocking the muscarinic cholinergic receptor on the heart with atropine would save your life if you were poisoned with what class of molecules?

acetylcholinesterase inhibitors

48. How is a norepinephrine breakdown enzyme an important target in the pharmacology of treatment for depression?

norepinephrine is obviously an "upper", so potentiating its action by inhibiting its breakdown would certainly be uplifting

49. "The nicotinic receptor is ionotropic." Translate: What is the transmitter? What is the molecular structure of the receptor? (Answer both.)

acetylcholine gates a channel

50. While administering Prozac to a patient with depression, the doctor needs to closely monitor (what?).

any suicidal thoughts or actions

51. In order to produce hamsters with large vs small testes, what did the lab prep technician need to do ahead of time?

put some on cycles of 8 hrs lights on vs 16 off and vice versa for the others

52. While light stimulates tells small-headed animals whether it is day or night, how is the pineal informed about the light-dark cycle in people?

input from the suprachiasmatic nucleus

53. Give one of the two possible reasons a diet high in tryptophan might make you sleepy.

precursor to serotonin and to melatonin

54. "Reuptake into the nerve terminus terminates the synaptic action of glutamate." How else is glutamate's action terminated?

it is also taken up into glia

55. What is sent throughout the brain from the Raphe nucleus?


56. A symptom of Parkinson's disease is bradykinesia. What is bradykinesia?

not moving much

57. Explain either (1) why schizophrenia was once attributed to a serotonin defect, or (2) why this hypothesis was later excluded.

an LSD trip seemed like psychosis and LSD affected serotonergic transmission, bur amphetamine induced psychosis was more similar to schizophrenia

58. How did your professor rationalize that action potentials would be smaller in manic-depression patients who are on lithium therapy?

the gradient of lithium plus sodium, seen by the channel, would not be as steep because the pump cannot pump lithium

59. Phosphatidylinositol and phosphatidylethanolamine, precursors for endogenous cannabinoids, are supplied from what compartment in the cell?


60. What is in the tail of Torpedo that made it useful for cloners interested in the nervous system?

lots of tissue with acetylcholine receptors

61. Why do you need to be very careful when you use muscle relaxation in conjunction with anesthesia?

while it is important for your patient or your research animal not to move, you must not paralyse without blocking pain

62. There is a muscle disorder where miniature end plate potentials are smaller than they should be, and it is not because the vesicles do not have enough acetylcholine. Answer either (1) What is the disorder? or (2) Why are the potentials smaller?

myasthenia gravis, fewer nicotinic receptors

63. Why would you give someone a beta blocker?

to decrease blood pressure at the level of beta adrenergic receptors in the heart

64. Phospholipase C converts a membrane phospholipid into (name or abbreviate one of the two).

IP3 or DAG

65. Why is caffeine an "upper?"

norepinephrine and epinephrine action is potentiated since the second messenger's breakdown by cAMP phosphodiesterase is inhibited